Horse welfare: nutrition and feeding

Feeding horses correctly is easy. It is not necessary to be able to talk with a stalk of grass in your mouth, nor to be bandy-legged, nor to have had years and years of experience. Correct information on feeds and feeding is readily available, it does not have to be stumbled upon through trial and error.

It is equally important to stress that there is no rigid or “special” ration that has to be fed to achieve a desired result. Provided the basic principles of nutrition are followed, ration constituents can and should be changed (slowly) according to cost and seasonal availability. Just one proviso - horses, unlike humans, do not particularly relish a change in diet. They prefer to eat what they are used to and some perseverance may be necessary when introducing something new. Even the same type of feed but from a different source can be enough to put group-fed horses such as weanlings temporarily off their feed.

Carbohydrates

The simplest carbohydrate is glucose. Broadly speaking, all carbohydrates from the simplest to the most complex first have to be converted into glucose by the body before they can be used for energy. In nature horses do not eat straight glucose or the next most complex carbohydrate sugar itself, which is composed of just two molecules of glucose bonded together. Horses do like very sweet things though, and readily accept sugar cubes as a tidbit. Also they find molasses highly palatable, though the very black molasses commonly used for sweetening and binding purposes has had much of the sugar extracted.

Starch is the principle high energy carbohydrate consumed by horses. It is made up of many glucose molecules bonded together and is found in the leaves of young plants and seed heads. As plants mature, their starch content moves from the leaves into the seed heads where it becomes much more concentrated. If these seed heads belong to the cereal grains (oats, wheat, barley, corn, etc) they are collectively called grain or sometimes concentrates. Grass, if it is not overgrazed, will develop a seed head and can be an excellent source of high-energy starch at certain times of the year. Unfortunately this situation seldom if ever exists on suburban agistment paddocks, which are more often weed infested and sadly overgrazed.

Cellulose and hemicellulose are the fibre part of feeds. They are complex carbohydrates or polysaccharides, being made up of multiple cross-linked chains of glucose. They form the framework of plants, so are the main components of the leaves and stems of grasses and hay and are the principle energy source for grazing horses. They need to be broken down by enzymes produced by bacteria that live in the horse’s caecum. High cellulose containing feeds are called roughages. Hay, chaff, the various brans and sugar beet pulp are all examples.

Once a plant such as a grass or cereal has gone to head it can be harvested. This means the seed head is removed mechanically, leaving behind the stubble, which contains a high proportion of a very complex carbohydrate called lignin. Another name for lignin is wood, which is indigestible by all animals except goats (some say) and termites.

The straw bedding used in stables is usually baled stubble. Some horses do eat their bedding probably as a displacement activity for grazing, but will derive no food value from it. Cattle on the other hand can make use of straw if it is laced with urea and molasses. It sometimes happens on properties that the poor old horse is expected to muck in with cattle being supplemented on straw and urea, but they cannot gain any nutrition from it, in fact urea in any quantity is toxic for horses.

The development of lignin particularly in the stems of plants once they have gone to seed has important applications in haymaking. In Australia, lucerne (alfalfa) is the main plant used for hay, the best of which should be soft and leafy with a fine stalk. It is traditionally cut when the paddock is 10% in flower. If the stalks in a bale of hay are coarse and spiky, it means the lucerne was cut too late or the plants were too old and the hay contains too much lignin. Obviously it is false economy to buy stalky hay for horses because it is cheap.

Fats

Fats are expensive compared with carbohydrates, but the increased energy yield may compensate. They have received much attention particularly for the feeding of endurance horses, but for various physiological reasons it seems only a small part of the diet should be made up of pure fat. Most of the energy should still come from carbohydrate sources.

Sources of fat for horses include the oilseed oils, corn oil and tallow. Rice bran also contains moderate levels. Tallow is a type of beef fat used mainly in candle making but it can be incorporated into stock feeds. It is debatable whether the feeding of oils and fats enhances coat shine as is commonly thought. The gloss of a healthy coat is due to natural oils produced by the skin, and horses that are generally well managed and fed will show it in the coat anyway.

Proteins

Proteins are sometimes called the building blocks of life because they are the main structural components of cells, and any time new tissues are being made, large amounts of dietary protein are required. The stages in an animal’s life when new tissues are extensively manufactured are growth, lactation and pregnancy.

Growth. Horses grow most rapidly from birth to six months of age. This tapers off between six and 12 months, but a horse fed adequate protein will have achieved 80% of adult size by 12 months of age. This is not fat but muscle and bone. If the protein level in rations for young growing horses is inadequate, they will be stunted. Stunted animals are not necessarily thin, in fact may be overfat if well fed on carbohydrates, but they will never be as big as their peers.

Lactation. Milk is far more than a sugary white fluid. It contains large amounts of protein as well as other nutrients which come ultimately from the mother’s food. If the mother’s diet is inadequate, particularly in early lactation, her milk will suffer and the foal will fail to grow properly.

Pregnancy. Up to the last few months of pregnancy the foetus is only a small drain on the mare. It is in the last three to four months that it really begins to grow and develop, requiring the mother to eat a higher protein diet.

Maintenance. Adult horses do have some requirement for protein, but it is small. This maintenance requirement is needed to replace worn out cells and keep the life processes ticking over. It is easily met by normal rations or average grazing. Any additional protein required to heal injuries, unless they are very extensive, is also met by a maintenance ration.

Work. It was once thought that protein was used up during hard physical activity, but this is not true. It is additional carbohydrate that is needed to meet the higher energy requirements. The traditional pre-competition meal of steak and eggs for human athletes has now been replaced by pasta and other high carbohydrate foods. Animals and humans in training do increase their muscle mass, but the small amount of additional protein required is easily met anyway by the higher intake of food. Protein can be used as an energy source but this should be avoided. Not only is protein expensive in comparison with carbohydrates and fats, but it leads to increased water consumption and increased urination with its attendant increase in ammonia production, which may be a factor in the development of respiratory problems in stabled horses.

Proteins are composed of chemically joined units called amino acids. There are 20 main amino acids, not many when considering the thousands of different proteins that can be made from them. A meaningful analogy is that just 26 letters make up the more than one million words in the English language.

Animals can make some amino acids for themselves but obtain the bulk by eating plant proteins, which are broken down by the processes of digestion into their constituent amino acids. These amino acids are then recombined into whatever proteins are required by the body at the time. Not all plant proteins contain all the amino acids at the same levels, therefore it is important that a variety of feeds is eaten to ensure that the necessary range is ingested. Natural pastures contain a variety of grass species, so access to a reasonable area and quality of grazing assures ingestion of the amino acids required.

Sources of protein. Most feeds contain at least the maintenance level of protein, which will be adequate for adult horses. Some feeds like lucerne hay and chaff contain much more than maintenance levels. Then there are the oilseed meals which contain higher levels still and are widely used to boost the protein levels in rations fed, for example, to growing horses and lactating mares. These oilseed meals are the high protein residues left after the oil has been extracted from soybeans, linseed, canola, cottonseed, etc. Some of the oilseeds are toxic in their whole state, but the meals are usually considered safe because the toxic principles are destroyed during the oil extraction process. However, soybean products should not be overused because at least in human nutrition it seems they may contain other factors deleterious to health if consumed in excessive amounts.

It is important to differentiate between the quality of a protein and its quantity. Quality refers to the range of amino acids a protein contains, while quantity simply means the amount of protein present. If it states on the lable that a bag of feed contains 12% protein, this is the quantity only and gives no indication of the quality. Animals raised on low quality protein diets, even if the quantity seems adequate, can suffer stunting and other protein deficiency related problems because of the lack of amino acids. Only if the missing amino acids themselves are supplemented is it economical to use low quality protein sources.

Soybean provides the highest quality protein of the oilseed meals, though canola (rapeseed) meal is equivalent. Skim milk powder is sometimes used in creep feeds and rations for weanlings and certainly provides high quality protein. However, it is twice the price of soybean meal and, although 100% digested in comparison with about 80% for soybean meal, there are no real additional advantages to its use.

Water

Requirements for water vary enormously depending on physical activity, ambient temperature and moisture content of the food being eaten, but horses should never have their water intake restricted except immediately after exercise when they are very hot, and that should only be for a short period. Give them a few sips to start with but before long they should be allowed to drink their fill. There have been reports of very hot horses foundering if allowed to drink gallons of water too quickly, also colic is a possibility.

Other than in the above situation and in certain recognised disease states, there is no such thing as a horse drinking too much water. A sweating horse can lose litres of water per hour and this must be replaced through drinking, otherwise dehydration and death will result.

Vitamins

The literal translation of “vitamin” is “vital for life”, and indeed vitamins are vital for life, but they are required in very small quantities. Any sort of half reasonable diet will contain adequate levels, and it is only under extreme or unusual circumstances that rations can be deficient. In developed countries it is very difficult to get a vitamin deficiency, in fact oversupplementation is a much more common problem and can cause poisoning. But while ever there are fortunes to be made out of the manufacture and sale of vitamin supplements, people will continue to be brainwashed about their benefits.

Fat-soluble vitamins

Vitamin A. Horses make their own vitamin A from a pigment in the feed called carotene. The only way they can get a deficiency is if they never receive any feed coloured green (grass, green hay) or orange (corn, carrots). Hay that is bleached or has been stored a long time can lose much of its carotene content, but it would be most unusual if horses, except under drought conditions, did not get access to carotene in some other way, at least before the liver stores of vitamin A run out. Vitamin A poisoning is well recognised in many species, with horses being quite susceptible. Symptoms include decreased growth rate and joint abnormalities.

Vitamin D. This vitamin is made by the action of ultraviolet radiation (from sunlight) on the skin and hair coat. As well, feeds such as sun-cured hay and chaff contain adequate levels. A deficiency is possible where horses are intensively stabled and/or rugged and only worked early in the morning in the dark. This situation can exist for some racehorses and may be further compounded by air pollution and smog, which cut down ultraviolet radiation. The feeding of artificially cured (not sun cured) chaff and hay represents another possible deficiency situation. But these are exceptional circumstances and more problems are caused by oversupplementation. In growing horses excess vitamin D causes lameness because calcium crystals are deposited around the joints. Mares oversupplemented during pregnancy give birth to foals likely to die from aneurisms (blood clots).

Vitamin K. It is not possible for horses to have a deficiency of vitamin K because they manufacture it for themselves. This vitamin is involved in blood clotting and may be useful in the diet of bleeders, though it will not prevent the development of the condition. Vitamin K toxicity causes sudden death due to kidney failure.

Vitamin E. This vitamin is widespread in feeds, making it difficult to imagine a deficiency situation, except possibly where horses are stabled all winter for climatic reasons and are fed old feed and have no access to grazing. Vitamin E acts as an antioxidant and is involved in correct muscle functioning, also it has a part to play in fertility in some species. However, there is no proof that additional supplementation with this vitamin aids these functions in horses. There is some evidence that it is beneficial in the treatment of certain rare neurological diseases, including wobbler syndrome.

Water-soluble vitamins

Vitamin C. Horses manufacture this vitamin for themselves, so it is not possible for a deficiency to occur except in a starvation situation. Claims made for vitamin C as an aid to the prevention of viral respiratory diseases in horses are unproven.

Vitamin B Group. There are more than adequate levels of all the B-group vitamins in good quality feeds and pastures. Horses make them for themselves anyway, and particularly in the case of the much overused and abused vitamin B12, experiments have failed to identify any benefit from supplementation.

Where horses are under stress, i.e., working hard and being fed high grain diets, it may be advantageous to supplement with thiamine (vitamin B1). Thiamine is sometimes called the anti-stress vitamin and may assist recovery and the maintenance of appetite. High levels of thiamine reportedly have the opposite effect, that of causing hyperexcitability.

The only other B-group vitamin worth specific mention is biotin. Brittle hooves do seem to respond to the daily feeding of biotin. However, it will do nothing for horses with good hooves.

Minerals

There are more than 30 known minerals, many of which are essential for life. They are substances that occur naturally as part of rocks and soils and include calcium, phosphorus, sodium, chlorine, potassium, iron, sulphur, iodine, cobalt, copper, zinc, fluorine, selenium, etc. Most are required in very small amounts. Some are needed in such tiny quantities that they are called trace elements. The role or even necessity of some of the minerals is still not known, including elements like lead and arsenic, which as all readers of murder mysteries will know are deadly cumulative poisons. But all the minerals can be toxic or have adverse effects if oversupplied; very small quantities may be essential for health, but more than that can cause ill health, even death.

The minerals each have a unique chemical symbol - Na (sodium), Cl (chlorine), Ca (calcium), P (phosphorus) and so on. Mostly they exist in nature as combinations called compounds. For example, when the elements sodium and chlorine combine chemically, the resultant compound is common salt, represented by the chemical formula NaCl.

As well as being essential for animal life, most minerals are also required by plants and are an integral part of their tissues. If a soil is deficient in some particular mineral, often plants will grow poorly on it. This is why fertilizers are used. Fertilizers may be organic (containing carbon) or inorganic mixtures of minerals applied to soils to correct deficiencies. Some mineral deficiencies (iodine and selenium are well-known examples) are area problems in certain parts of the world. Australia as a whole is phosphorus deficient, which is counteracted by the widespread use of superphosphate fertilizers in agriculture. Animals acquire most of their minerals by eating plants in fresh or cured or harvested form, also from natural water supplies such as bores, dams and creeks, although water sources of minerals are often in the nature of folklore and overrated.

Perhaps one of the most meaningful laws of science is that matter cannot be created or destroyed. Plants and animals that live and then die and decompose on the one area of ground have their minerals and other components returned to the soil in that same area so that the cycle of life can continue. Soils become deficient in minerals when what is grown on them is removed - as crops that are harvested, or animals that eat the crops or grass but die or are slaughtered elsewhere.

Calcium and phosphorus.These two minerals are the main constituents of bone. A deficiency of either can cause bone weakness and fractures. They need to be taken into the body in a certain ratio, which should be in the limits of 1.6 to 1.2 of calcium to 1 of phosphorus. Most horses ingest a more than adequate amount of both minerals, with problems arising due to imbalance rather than deficiency.

Excess phosphorus in relation to calcium is much more harmful than the reverse, because even if there is adequate calcium as there usually is, the excess phosphorus prevents it being absorbed from the digestive tract. This leads to weakening of the bones and lameness, and calcium needs to be added to the ration to correct the imbalance and restore the right ratio of a higher level of calcium than phosphorus. In terms of practical feeding, the things to remember are that the grains contain moderate phosphorus levels, lucerne hay and chaff are high in calcium, and bran contains a high phosphorus level.

When rations are fed that contain fairly equal quantities by weight of grain and lucerne, the calcium and phosphorus will be balanced. Normally it is only the heavily grain-based, low-lucerne ration that will require calcium supplementation. Beware of adding DCP (dicalcium phosphate) or bone powder to such rations, they contain phosphorus as well as the desired calcium and can exacerbate the problem. It is less common to get a handfeeding situation where both calcium and phosphorus, or phosphorus alone, need to be supplemented. The feeding of lucerne hay on its own, with little if any access to grazing or any other type of feed, may represent such a situation, requiring additional phosphorus.

Over a period of time it can take only a small oversupply of phosphorus in relation to calcium to lead to bone changes. This manifests initially as an indefinite, shifting lameness. Unfortunately, diet is frequently overlooked when investigating possible causes of this type of lameness.

A severe oversupply of phosphorus occurs when large quantities of bran are fed. Considerable amounts of calcium are released from the bones to try to compensate, causing them to soften and swell. This condition is known as bran disease or big head. It is first noticed as a variable lameness that progresses to stiffness and reluctance to move. The head then develops swellings due to demineralization of the skull bones. Breathing through the narrowed nasal passages becomes laboured and noisy.

Another way horses can develop big head is by grazing certain introduced grasses. In Queensland, the main culprits are buffel grass in inland parts and setaria on the coast. Large areas are planted to these grasses, they are excellent for cattle but bad news for horses. They contain compounds called oxalates that bind up calcium and make it unavailable, the end result being the same as for the high phosphorus story. Cases can also occur on green panic, para grass, pangola, kikuyu and guinea grass. However, the problem is lessened considerably if these grasses are only part of a mixed pasture, as they usually are. Where horses are forced to graze virtually pure stands of oxalate-containing grasses, the big head problem can be kept under control by supplementing with calcium, usually in the form of a limestone/molasses lick. Finely ground limestone is widely used in all types of feeding situations where calcium supplementation is required, 30 grams of limestone yielding 10 grams of calcium. More refined and purer sources of calcium include calcium gluconate. Dicalcium phosphate (DCP) powder can be used where both calcium and phosphorus need to be supplemented.

Iron. This mineral has been sadly abused in the horse industry, although there is increasing awareness nowadays about the dangers of toxicity by oversupplementing with iron. Not only do most feeds and pasture grasses contain well in excess of the minimum requirements, which are very low in any case, but long before it was fashionable to recycle things the animal body was recycling iron with the greatest efficiency, so that very little is lost anyway under normal circumstances.

The only possibility of an iron deficiency occurring is if the horse has suffered severe or chronic bleeding or is carrying a heavy parasite burden. Obviously the cause has to be treated first, not the iron deficiency. Iron toxicity is a much commoner problem than deficiency, in fact horses have been known to drop dead after an iron injection, not to mention the awful tissue reaction that often occurs at the site, with associated swelling and pain. Oral iron supplementation can lead to death in foals, and in adults an increased susceptibility to bacterial infections and bone abnormalities due to an induced phosphorus deficiency.

Iodine. There are certain parts of the world, including some small pockets in Australia especially in Tasmania, where iodine deficiency causes swollen thyroid glands (goiter) and other associated symptoms. In these so-called goiter areas, plants will be deficient in iodine and animals have to be fed supplemental iodine, usually in the form of iodized salt. However, iodine requirements are exceedingly small, an estimated teaspoonful over the life of the animal, and toxicity can easily occur.

It has been fashionable from time to time for studs to feed dried kelp (seaweed) to brood mares or add it to drinking water. This practice usually stops abruptly when the dead or weak or crippled foals start arriving. Kelp contains high levels of iodine which poisons the unborn foal. In older animals iodine toxicity results in goiter and its associated symptoms, the same as for iodine deficiency. Some sources of kelp contain high levels of heavy metals which can also become poisonous and is the reason kelp has largely been withdrawn as an iodine supplement for humans. It is also noteworthy that since iodine-based disinfectants are no longer used in the dairy industry, iodine deficiency in humans is on the increase.

Selenium is another trace element that can be deficient in soils in some areas of the world and may need supplementing, but it very easily causes poisoning (shed hoof disease in horses) if even slightly oversupplied. Some Australian soils are high in selenium and plants grown on them can cause poisoning, particularly those known to accumulate selenium.

Salt. Salt is a vitally essential mineral and is really the only one, aside from calcium, that often requires supplementation on a regular basis. As a component of body fluids, salt helps to maintain a steady environment for all the cells and tissues. It is the main ingredient in electrolyte preparations. “Salt” is available as table salt, coarse salt, cooking salt, rock salt, sea salt and natural salt. Some of these sources have more impurities than others and may be finer or coarser, but the NaCl component in all of them is exactly the same with no difference in properties.

The crusty material left on the coat of a horse that has been sweating is almost entirely salt. Large amounts of salt can be lost in this way, more than can be made up for by the naturally occurring salt in feed. Thus horses in hard work that are sweating heavily and regularly will require salt supplementation. This is best done by making sure there is always a handful in the bottom of the feed tin. Salt is the only mineral that horses will eat voluntarily if they need it, so can be provided free choice in this way. Forcing horses to eat more salt than they want, e.g., by dissolving it and mixing it through the feed, will lead to rejection of the feed and a hungry horse. Various types of salt blocks can also be used, though there is some doubt whether horses have a rough enough tongue to adequately utilise them, particularly when there is a need to take in considerable quantities of salt.

Potassium is also lost in sweat, but except in unusual circumstances is adequately replaced by naturally occurring supplies in most forages and grains.

The vast majority of horses worldwide exist just on grass and times can become pretty lean for them during winter or droughts, even on large acreages. This situation is exacerbated where horses are more intensively managed on small areas of land where overstocking all too readily occurs. However, there are many harvested feedstuffs available that can be used to either supplement the diet of grazing horses or maintain them fully where no or little grazing exists, or where they are stabled. These feedstuffs have differing energy values and other properties that make them more or less appropriate to particular handfeeding situations.

Pastures

In a good season and where stocking rates are appropriate, horses will do as well on grass as on hand feeding. In south-east Queensland there is a vast difference between the quality of summer versus winter grazing. The abundance and quality of native grasses can decrease to almost zero during winter, though many native pastures can be improved by the introduction of imported grasses. Paspalum and rhodes grass are common in south-east Queensland and there are other suitable species. One of the best ways to improve any pasture is to introduce legumes such as the clovers and lucerne. These provide more soil nitrogen which makes the grasses grow better, also they are higher in calcium and protein than the grasses. However, they are not suited to all areas, often having strict seasonal and rainfall requirements.

Horses are notorious for being selective grazers, also they prefer shorter species, meaning they will eat out a patch of grass while ignoring an adjacent section. Using cattle to follow horses on a rotational basis makes better use of a pasture and assists in parasite control. Mowing and slashing are alternatives and help with weed control as well.

Concentrates

The term “concentrates” mainly refers to the cereal grains, also sometimes called “hard feed”. They are high energy, starch containing feeds with a low to moderate protein content inadequate for growth. Horses really enjoy grain and it is often more economical to supplementary feed with grain rather than hay if some grazing is available to provide roughage. Included under the concentrates umbrella are the high-protein feeds, such as the oilseed meals, particularly important in the feeding of growing and lactating animals.

Grain feeding

It is important to stress that the health, good condition and high spirits of the adequately fed hot-blooded horse should never be confused with the sometimes unmanageable behaviour of the one that is overfed and underexercised. Conversely, it is very poor horsemanship to underfeed horses in order to control them. Horses in good condition and health are naturally spirited animals and simply may not be suited to everyone, no matter how strong the desire to associate with them.

The grains contain no special factor that makes horses difficult to handle. Neither are they heating. In fact the digestion of roughage generates more heat and creates much more internal warmth than the digestion of grain. But the energy in grain is much more concentrated, more quickly available and cheaper than that in roughage. Worldwide, grain supplementation is the basis of economically feeding horses in group situations. Thousands of stud mares - wet, dry, in foal or empty - are run on pasture and supplemented with grain as needed and nothing else. They do not become raving lunatics, and neither will your weekend hack if given a hatful or two of grain. The cost saving of feeding some grain in place of all hay will be a pleasant surprise as well.

The grains (high-energy concentrates)

Corn. In some countries corn (maize) is the most widely fed grain. It tends to be cheaper than oats and is higher in energy, but only slightly. The problems than can arise from feeding corn are not due to its energy content but its weight and lack of husk. A pint, quart or litre container full of corn is much heavier than the same measure of oats, so it is easy to overfeed corn if feeding by volume rather than weight. It is traditional to crack corn or process it in some other way to improve its digestibility, but opinions differ whether this is necessary. It is such a large grain that horses are forced to chew it anyway, and it is particularly prone to spoilage once cracked.

Barley. Barley is an excellent grain for horses with an energy level the equivalent of corn. But it is a smallish, hard seed with little husk and does need processing by crushing or steam rolling to improve digestibility, or soaking for several hours in water. The time-honoured tradition of boiling barley is not necessary, in fact destroys some of the protein. Although heating is used commercially in the processing of many of the grains, the object is not to cook the grain but to break the chemical bonds in the complex starches. This helps ensure that much of the starch is digested in the small intestine before the grain passes through into the caecum. Too much caecal digestion of starch causes various digestive disturbances, resulting in loss of appetite and colic.

Sorghum. Sorghum and its relatives such as milo are just so-so grains for horses, mainly because palatability and protein quality are low and the seeds are very small and hard. However, their energy level is good and they are quite widely used in group-feeding situations where they can be freshly hammer milled on-farm as required and mixed with other feeds. Also they are cheap grains with good binding properties and are the basic ingredient in many pelleted feeds.

Pollard and millrun. Pollard is basically reject or second grade flour. Millrun is a combination of pollard and bran. They are good energy sources but highly fermentable in the digestive system and can cause upsets. It is recommended that no more than a kilogram per day be fed, mixed thoroughly with the rest of the feed. Pollard has a reputation as a superior fattening agent, but any of the grains or their processed products will fatten if fed above energy requirements.

Pellets. These are convenience or “fast” foods for horses. They are quite nutritionally sound provided they are made by a reputable company, but they do not have the special or magical properties sometimes hinted at by the manufacturers. To be competitive in the marketplace, pellets are often based on the cheap grains sorghum and milo. Additional amino acids and various other bits and pieces are added to make them nutritionally adequate. Generally speaking, the more expensive pellets use a mixture of better quality grains and may also contain lucerne, or lucerne meal itself can be pelleted. Some studs and other establishments feeding large numbers of horses have their own pellets made up, which can be quite expensive compared with hand mixing and feeding the raw ingredients, but the convenience may warrant it.

Pelleted feeds are more digestible, are very low in dust, take up less storage space, are easily transportable, and horses cannot sift out the ingredients. On the negative side, they may be eaten too fast leaving horses standing around in stables with even less to do than normal so they develop stable vices all the more quickly, also a prolonged gap between meals can lead to digestive disturbances. It is recommended that pellets always be fed with other more natural feeds, either hay or chaff or even some additional grain, even if they are marketed as a complete feed.

Commercially mixed combinations of the various grains and/or chaff are available, they may be of higher quality than any of the pelleted feeds, but again factors such as freshness, spoilage risks, cost versus convenience and quality will dictate their use. These mixtures are sometimes mixed with molasses and marketed as “sweet feeds”, added advantages being that they are low in dust, have high palatability and the ingredients are better bound.

High-protein feeds

Roughages

These are the hays, chaff and bran. They are composed mainly of cellulose and are the bulky, medium energy feeds and an essential part of the diet. Horses can do without grain but not roughage. Evidence has been mounting over the last decade or so that a lack of roughage in the diet of stabled, high-performance horses is the main cause of gastric ulcers which are being diagnosed with increasing frequency since endoscopy has become more routine.

Bran. This is a popular and time-honoured feed for horses, and it does have good protein and energy levels, but its high phosphorus content interferes with the uptake of calcium. At its most extreme this leads to bran disease or big head. However, it is fine to use some bran, a kilogram a day is not a problem, provided the calcium side of the ration is adequate. Also it makes an excellent hot poultice for hoof injuries. Most bran fed to horses is wheat bran, but oat bran is occasionally available, also rice bran is proving popular as a high fat source.

In years gone by, warm bran mashes were a great cure-all for problems ranging from colic to after foaling pick-me-ups. The look and smell of a hot bran mash may be comforting to the owner but doubtfully does the horse much good, in fact the mild scouring that results is probably due to a temporary upset of the gut microflora rather than a sign that “bad substances” have been flushed from the intestinal tract.

Lucerne hay and chaff. Lucerne (alfalfa) hay is the roughage par excellence. It has had all sorts of criticisms levelled at it but they are unfounded. It does not make mares abort or cause racehorses to lose form. What it does do is provide excellent protein, energy and calcium for all classes of horses. The only slight criticism of lucerne is that if feeding it entirely on its own with no access to grazing or any other type of feed, the use of a phosphorus supplement may be warranted.

Lucerne is available as either hay or chaff and can also be pelleted. Chaff is merely chopped up hay, it has no other ingredients or additives, although for chaff making, the best quality hay is usually used. Good quality fresh lucerne hay should weigh about 40 bales to the tonne. It loses its colour and moisture content with storage and consequently some of its weight, but not necessarily its nutrient value; properly made lucerne hay will keep in good condition for at least a year, often much longer. If it becomes very dried out and spiky, it can be much improved by sprinkling with water an hour or two before feeding. Hay stored for many years has been used in drought situations and still provided worthwhile nutrition.

The best hay is made from lucerne cut when the paddock is about 10% in flower. If cut any later it starts to lose its nutritive value and the stems becomes coarse with too much lignin for horses. Good hay has a pleasant non-fermented smell, is soft and leafy and has a fine stalk. A bale should feel heavy when picked up but not heavy like a lump of lead, meaning it is wet. Making hay for a living can drive people to an early grave. That old cliche about doing it while the sun shines is all important. If hay is baled too soon or is rained on while curing in the paddock, it will heat up and become mouldy. You can pick hot hay by easing your hand down into the middle part of the bale. En masse it has a strong fermented smell, also it can generate so much heat once stacked that it can catch on fire. Mouldy hay, the type that pours forth clouds of blue smoke-like dust on being broken open, should not be used; many of the moulds are toxic.

Lucerne hay becomes prohibitively expensive during the winter, which also coincides with its time of most demand. If there is a drought on as well, expect to pay up to three times the summer price per bale or tonne. It makes a lot of sense to build a hay shed even just for a few horses. Buying hay when it is plentiful and cheap and storing it in preparation for the winter or dry times can save a great deal of money.

Oaten and wheaten hay and chaff. These are medium energy roughages but are very low in protein, not having a maintenance level even for adult horses. They are made from the respective cereal crops cut before they are in full head. The actual grain content in them is quite variable and this will have an effect on their value as feedstuffs. Unfortunately they have a fanatical following amongst some horse people but their nutritive value is limited, particularly in comparison to lucerne. They do add bulk to a ration though, and are useful in the feeding of hard working horses to help maintain the correct roughage/concentrate ratio. Also, if left as long-stemmed hay, they give stabled horses something to chew at between meals without providing much additional energy to the total diet.

Barley hay. Sometimes cheap barley hay becomes available, particularly if a drought is looming and there is doubt whether a crop will reach harvestable stage. However, barley hay should always be fed within reach of a hose. The long awns on the heads of barley have a magnetic attraction for the inner lining of the mouth. Before long there will be some unhappy looking horses standing around not eating and dribbling streams of saliva. This is when the hose becomes necessary, to wash out their mouths to get rid of the barley awns.

Grass hay. Sometimes a paddock of ordinary grass is locked up (not grazed) and cut for hay instead. Depending on the grass species and stage of cutting, this can make quite satisfactory hay. Timothy hay is widely fed overseas. Some legume/grass mixtures, such as the popular rye grass and clover of southern states, make very good quality hays. Always judge the suitability of any hay for horses by the coarseness of the stem and amount of leaf.

Concentrate/roughage ratio

A survey some years ago of racing stables in Brisbane showed that almost invariably the roughage/concentrate ratio used was close to 1 to 1.2, meaning 1 kg of roughage was fed for every 1.2 kg of grain. A small portion of the roughage component included cut green feed in most cases. Some endurance horses surveyed seemed to be on a 1 of roughage to 1.4 of concentrate ratio, but most of them had access to some grazing as well, so probably the 1 to 1.2 ratio that seems safest for working horses was not being exceeded.

This ratio is generally not appropriate for ponies or draught horses, both require a much higher proportion of roughage in the diet, though as with any other horse, amount of work is a key factor. Ponies will get fat “on the smell of an oil rag” and fat ponies are prone to founder. Draught horses can become uncontrollable on high grain diets, and there is nothing worse than seeing one of these large kindly animals up on his hind legs dragging some unfortunate handler round a showring, or bolting loose through a crowd of spectators.

Mixing concentrates with roughage

Of course, horses have to be gradually introduced to their full quota of grain and in fact in the early stages it may be best to feed it with chaff. The reason for not continuing with the chaff any longer than necessary, especially when supplementary feeding a number of horses, is its expense. Chaff is simply chopped up hay. It is much more economical to feed hay unless you have your own chaff cutter. Many group-fed horses, brood mares for instance, are given a portion of grain individually and have access to communal hay in hay racks.

Feed additives

Feed additives are generally thought of as being vitamins and minerals, but there are other bits and pieces that can be added to horse rations, some of which have a valid use.

Molasses. This black sticky substance, a byproduct of sugar milling, is variable in energy content depending on how much sugar has been extracted from it, but it is a really favourite food of horses once they acquire the taste. It is an excellent binder and is widely used in “sweet feeds” for this purpose, also it disguises unpleasant tastes such as limestone and other additives. It is also a good natural source of the electrolyte potassium.

Bread, carrots, cooked vegetables. All these have nutritional value but expense usually places them in the tidbit category, with the possible exception of carrots. None of them are particularly liked by horses initially, nor do they have performance-enhancing properties above those of normal feedstuffs. Because of their carotene content, carrots are a vitamin A source, but one or two a few times a week is adequate.

Sugar, honey, maltose, dextrose, glucose. All are simple carbohydrates which are more quickly converted to energy by the horse than starch or cellulose. Sugar is in the tidbit category, the others are sometimes used in the diets of performance horses before competition. The belief is that they provide a source of instant energy, and this is true, but it is a bit too instant. They would need to be administered while the horse is actually competing to be of any real benefit, which of course is not possible.

Bentonite (montmorillonite). This natural clay is said to have a thousand uses. It forms the basis of many clumping cat litters, although it has fallen out of favour for this purpose now, as it can cause health problems for cats. But it is widely used in construction, also in the manufacture of feedstuffs as a binding agent for pellets and other types of processed feeds, and it can be added to the rations of feedlot cattle to neutralise excess acid produced in the digestive system due to the high grain feeding. It may also be beneficial for horses for a similar reason. It is well known that horses on a high grain diet can go off their feed, which may be due to a variety of reasons including gastric ulcers, which are probably mainly the result of a wrong roughage/concentrate ratio and/or no access to grazing, but the passage of undigested grain through to the caecum resulting in caecal acidosis is perhaps another factor. The feeding of a grain like oats which has a substantial hull, the processing of other grains to improve digestibility, and not exceeding a 1.2 to 1 concentrate to roughage ratio or feeding even more roughage above those guidelines will all help prevent the problem, but the addition of bentonite to the ration also appears to assist, at least in some cases.

There are more myths and old wives’ tales about the correct feeding of horses than any other animal. Perhaps it is because horses are performance animals rather than meat or milk producers, so there are no real objective guidelines to measure the value of one feeding program over another. Also, up to a point, good horses will perform well irrespective of how they are trained or fed, so it is easy for owners of a successful horse to think they must have stumbled on some secret formula. But there are no secret formulae or ingredients or superfoods that give that winning edge, rather it is a matter of common sense feeding management combined with sound nutrition principles. Different ration ingredients can and should be substituted depending on seasonal availability and quantities adjusted according to the individual horse. Horses should always be fed to condition and even the most hardworking of them should never distinctly show any rib.

Calculating rations

For convenience, the following information is based on the requirements of the average hot-blood (for example, Thoroughbred) of 450 kilograms (1000 pounds) mature weight. Horses of other types and mature live weights will have different requirements.

Feeding young growing horses

The most important aspect of feeding young growing horses is to provide them with adequate protein. This is where high-protein supplements such as soybean meal enter the picture. Growing horses also need plenty of energy from carbohydrates, but energy without sufficient protein will merely result in fat weanlings and yearlings, not well-grown ones. A word of caution - the feeding of protein above requirements may result in joint problems later in life. Also, adult size is fixed by heredity, and this cannot be exceeded no matter how well the animal is fed during the growing period.

People sometimes make the mistake with Thoroughbred foals, for example, of weaning them then turning them out into a paddock to survive the winter on a bit of hay. Comes time to get them ready for yearling sales, and they are brought into stables for three months or more and absolutely stuffed with grain and probably a protein supplement as well. Usually they also have insufficient exercise, so the end result is a very fat yearling, smaller in stature than it should be, with contracted tendons and sore feet. It is not difficult to work out why - overfat because of too much energy intake, small because of insufficient protein during the critical growth phase, and the feet and limb problems are due to lack of exercise and too much weight, often compounded by excessive feeding of protein at this stage, when it is way too late anyway.

Creep feeding

There are various types of creep feeders, including one that is just a single low rail which only foals can get under, while another is a small yard with foal-sized openings at either end. Some are built on skids so that they can be pulled by tractor from one paddock to another. But whatever the design, the creep needs to be solidly and safely constructed, with no sharp angles or projections and definitely no wire or steel posts. Also it should have at least two entry/exit points. Tractor tyres cut in half make excellent feeders to place in the middle. Anything metal with an incurving rim, such as old washing machine bowls, should not be used because they can be murder on the lower limbs if the foals decide to play in their food. Protection of the feeders from the weather is ideal, but often difficult because of safety considerations. If feed does get wet, it should be removed and replaced with fresh material. Access to lucerne hay should also be provided.

Creep feeds are basically a mixture of grain with a protein supplement, which in very young foals may be milk powder. This can gradually be replaced by soybean or canola meal as the foals grow. A calcium supplement will also be required, although foals will get plenty of calcium and phosphorus from their mothers’ milk. More of the creep will be eaten with age, though intake will vary depending on the quality of the pasture the mares and foals are grazing.

The weaning period

Once properly over the upset of weaning, a six- to seven-month-old weanling will be eating per day up to 5 kg oats, 1 kg or a bit more of soybean meal, 2 kg lucerne chaff and/or hay (though hay should be available ad lib), perhaps some bran, plus a calcium or calcium/phosphorus supplement. Access to good quality grazing is desirable but not always possible at least in the early weaning period, and will influence the amount of feed eaten.

Yearlings

Nowadays yearlings are not being brought in to stables so early in preparation for sales, they are being less stuffed with feed once they are stabled, and this has resulted in sounder and more athletic young horses. Far from being a time of maximum feeding which is how some people approach it, the stabling time before the sales should be a tapering off period. Yearlings that have been properly fed and are well grown to this stage should have their concentrate intake reduced and be converted to a higher roughage ration, including freshly cut green feed if possible. A small plot of irrigated lucerne or similar can provide a remarkable quantity of green feed, a strip of which can be cut each day with a scythe or power reaper.

Exercise for many sales yearlings takes the form of ten to 20 minutes a day of frenetic activity by lunging in a round yard. This is not the best sort of stress for young legs, even though horses running free do circle and prop and turn, they mainly run in straight lines. Some studs now have a setup whereby yearlings can be safely run out to exercise at will and for a longer period. Also yearlings can be let out in safe individual yards to get more of their own exercise, especially at night when the sun will not damage their coats.

Feeding for Reproduction

The Stallion

Stallions should start the breeding season in good working trim. Too many of them are kept in small yards where they cannot get sufficient exercise. Stallions, after all, are the mainstay of any stud, and as explained more fully under Horse welfare and breeding more emphasis should be placed on providing safe paddocks where they can graze and exercise, especially in the off season. During the stud season some stallions become real pains in the neck, and in fact may need closer confinement to stop them running the fence constantly. Another solution is to accommodate them where they can always see at least some of the mares - this often has a remarkably calming effect on them, also improves libido in some cases.

All these factors make it difficult to state exactly how a stallion should be fed. In the off season, unless being worked regularly, they require only a maintenance diet. During the stud season, feed to condition. Some stallions are used to cover mares twice and occasionally three times a day, others only a few times a week. The production of sperm requires no special feeding method or ingredient above that available from a normal working ration.

The Mare

Pregnancy. Mares maintained in good general condition do not require additional feeding until the last one third of pregnancy. This coincides with the harshest part of the year (winter into spring), so allowance will also have to be made for a decrease in pasture quality. Mares in late pregnancy will require 8 to 9 kg lucerne hay daily, or half this amount of hay with about 4 kg oats, which will generally be the cheaper option. Calcium and/or phosphorus may also need to be supplemented. Three- to four-year-old mares are still growing themselves, so may require additional feed to maintain condition.

Lactation. Like cows, mares produce more milk early in their lactation periods than later. As the foal grows and fends more and more for itself, the milk supply tapers off until it ceases at weaning, due to the pressure of unused milk in the udder. If a foal is left on the mare to be weaned naturally, she will continue to produce a reducing amount of milk until a month or so before the next foal is due.

Peak lactation occurs in the first two months after foaling. During this period the mare has a really huge demand for food. Virtually everything she can eat goes into her milk, in fact some mares lose weight irrespective of how well they are fed. They simply cannot physically eat and process enough feed to maintain their milk supply and their own body weight. It takes a top quality pasture to support mares without handfeeding at this time. To fully maintain them on handfeeding alone, something like 6 kg oats and 10 kg lucerne hay and/or chaff per day will be necessary. If grazing is reasonable, the quantities can be reduced accordingly.

Feeding horses in work

Most of the mythology of feeding is associated with rations for working horses. However, there are no secret ingredients or special diets that will make a silk purse out of a sow’s ear, or a Phar Lap out of a donkey. Nor is the feeding of working horses an art only ever learned by a privileged few; it is merely a combination of sound nutrition principles and common sense.

A sad fact of life and a cause of many of the myths is that people generally are not interested in how the body works, only in how to make it perform better. It is important to keep in mind the saying “good horses make good trainers”. There are no doubt many examples of horses being top performers despite less than optimum feeding and management regimes.

Work can be classified as slow or fast, of short or long duration. The faster the work, the shorter its duration of necessity. Horses that perform best at speed are more heavily muscled than those that excel over a distance, and these sort of factors have to be taken into account when deciding whether a horse is in good working trim or not. To the untrained eye, a racing Quarter Horse at peak fitness may look too fat, an endurance horse too mean and lean.

If there is any “art” in feeding it is this: once a horse is in full work and eating a ration approximate to calculated energy needs, it is then up to the feeder to fine tune the intake in accordance with condition and performance.

Nutrients required for work

It is the energy content of working rations that is the important consideration. The energy needed varies from 5kcals/hour/kg body weight for slow work such as walking, to 40kcals/hour/kg body weight for strenuous work like climbing at speed.

Grain feeding is necessary for hard or fast work, otherwise the horse will be unable to take in enough energy to perform the work and maintain condition. A side effect of grain feeding is a reduction in the weight and bulk of the gut contents, which also aids performance. The herring-gutted appearance of, for example, a racehorse has more to do with decreased bulk in the intestines than a tightening of muscles. Conversely, horses trying to eke out an existence on poor quality grass will have large abdomens (grass belly) because they need to process so much material to get sufficient energy to survive.

Check list for feeding working horses

Endurance horses

One thing is certain - you can never overfeed an endurance horse provided you stick closely to the recommended concentrate to roughage ration (1.2 to 1) and always halve the grain on days off. Dedicated endurance riders will tell you that endurance horses should not by choice be stabled, confined to small yards or unnecessarily rugged. Grazing is recommended, although lightness of gut contents is an advantage for competition purposes, therefore it makes sense to restrict grazing, in fact the whole roughage component of the diet to some extent prior to an event, though not at the expense of unduly stressing the horse or causing digestive upsets.

Weekend riding

The best way to determine whether a weekend horse, or any horse for that matter, is getting sufficient to eat is by condition and behaviour. Keep a close watch in particular for that first tell-tale sign of ribs showing. There are some angular, raw-boned types that never will carry much condition, but they still should not show any rib. If they are, then they need more feed, and through the week as well as on days they are ridden.

Racehorses

Standard work for a racehorse consists of alternate slow and fast days, though neither are of long duration. A fast day may be as little as a warm trot and a 400 metre (two furlong) gallop, while a slow day can be any mixture of trot, canter or pace work over a distance seldom exceeding four kilometres. There are many possible combinations in between depending on stage of fitness, proximity to racing and whether the horse is a sprinter or a stayer.

Show Horses

It is definitely not the aim to present a show horse trimmed down like a racehorse, but neither is the overfat, overfed hack desirable. It is no fun to be crow-hopped around the ring, especially when the judge is looking. So show horses should be fed a ration that has a higher roughage than concentrate component. It does not matter much what the roughages and concentrates are, provided the basic principles of nutrition as already discussed are followed. However, no such sweeping statements can be made about the feeding of eventers, which must truly be an art and very dependent on the individual horse because of the extreme performance demands placed on them, from the decorum and discipline of dressage one day to the all-out effort of showjumping or crosscountry the next.

Feeding for Maintenance

In a total handfeeding situation, maintenance requirements for a 450 kilogram horse will be covered adequately by 8 to 10 kg grass/legume hay, or 7 to 8 kg lucerne hay, or 3 kg oats plus 4 kg lucerne hay. If the horse does become too fat or too thin, adjust the intake accordingly.

Orphan foals

Reasons for orphan foals include death of the mare during or shortly after foaling, inability to suckle the foal (no milk, udder melanoma), rejection of the foal by the mare. In the stud situation, assistance is usually immediately available, but in unsupervised foalings of recreational horses, orphan foals may not be found for a while and be in worse condition than they look.

Initial assessment

Stomach tubing with colostrum and/or administration of IV fluids may be necessary. If too weak to stand and/or behaving in a “rag doll” fashion, orphan foals have a very limited chance of survival.  Lameness can indicate joint ill. Also check for yellow gums, conjunctiva (jaundiced foal syndrome).  

Feeding

It is imperative that foals receive colostrum in the first 12-18 hours following birth. Foals are particularly prone to neonatal infections (e.g. joint ill) if colostrum intake is inadequate. Give 750-1000ml/10 Kg in 6-8 feeds by bottle, ensuring a bare minimum intake of 1.5 to 2 litres. A lamb teat is suitable for foals. Many studs have frozen colostrum on hand, it keeps well for at least a year. Also there are commercial colostrum banks, depending on locality. Cyberfoal (www.cyberfoal.com) is a free site listing availability of and requests for colostrum (and nurse mares) worldwide.

Bovine colostrum (stored, frozen, dried) is a satisfactory alternative. 

Colostrum can only be given by mouth within the first 24 hours of birth. After that, the antibodies it contains can no longer be absorbed from the foal’s digestive tract. If a foal is more than a day old and there is doubt whether it suckled before the mare died, then artificial antibodies should be given by injection by a vet.  A serum test can be done to evaluate IgG antibody status and an IV infusion of equine plasma can then be given to elevate the antibody levels.

Thereafter it may be possible to foster the foal onto a nurse mare, or alternately use foal milk replacer (e.g. Biolac, Wambaroo) according to directions (general rule is to feed small amounts frequently, gradually increasing the total intake).

Cows milk, goats milk and calf milk replacer can also be used.

Foals can be taught to drink from a bucket ad lib from an early age, although it is customary to bottle feed them for a few days to ensure they are healthy and drinking well. A method that works as well as any other is to let the foal get a bit hungry then present him with a bucket of the milk replacer. Stick a finger in his mouth to encourage sucking then gently lower his muzzle into the bucket of milk, still on your finger, being careful to ensure milk does not cover or enter the nostrils. If the foal pulls away, calmly start the process over again rather than using force.

Once the foal is drinking properly, milk can be made available ad lib. The bucket should be hung at a convenient height out of the sun. General cleanliness is of utmost importance. The mixture must not be allowed to go sour, it should be made up hygienically and all equipment scoured daily. 

Ensure that water is provided separately.

By the 10th day, in addition to the milk replacer, the foal can be started on a grain and milk powder mixture (initially 25% protein). Hay should be provided as well and grazing in a small clean (worm free) area. By the 30th day, the weaning process can begin. Gradually decrease the bucket milk so that by 2 months the foal should be fully weaned and eating a grain, milk powder and/or soybean meal and chaff mixture plus hay and grazing. As the foal ages, the protein percentage of the ration must be reduced in relation to the total energy intake, to avoid joint problems.

Note that orphan foals will often develop diarrhoea at 7-10 days of age, the so-called “foal heat scours” exhibited by foals on their mothers at this time. If there is no fever and the foal is otherwise well, treatment is unnecessary. 

Case study: Orphaned thoroughbred foal. 10^th day drinking about 18 litres of milk replacer a day, 27 litres by day 20, plus solids (grain, milk powder and hay). 30^th day, 36 litres of milk replacer plus a good quantity of solids. 1 to 2 months, milk was gradually decreased and soybean meal substituted for the milk powder in the grain mixture, which was made available ad lib.

An orphaned foal should be reintroduced to its own kind as soon as possible, preferably by weaning another foal early to keep it company, or by being close to or in the vicinity of other horses. Goats have been used as companions for orphan foals, in fact have been used to nanny foals.